This invention relates in general to electric stringed instruments and, more specifically, to an improved instrument which can selectively produce more variety of banjo sounds and louder banjo sound than previously possible.
Since the development of electric amplification techniques and equipment for stringed instruments many efforts have been made to both produce higher quality sound and to produce new and different sounds than those produced by prior instruments but all attempts have left banjos with a limitation of sound volume significantly lower than electric guitars due to feedback generated by the head of the banjo when the sound vibration of the music causes excessive vibration of the head. Prior electric banjos with wood bodies do not have volume difficulties but lost the banjo sound because the essential taut membrane was discarded. Early attempts at electrically reproducing banjo sounds used a pickup transducer placed in contact with the taut membrane or the string supporting bridge or both. Law, in U.S. Pat. No. 3,780,202, placed the pickup on a movable bracket within the banjo housing to contact the backside of the taut membrane. While this arrangement does very well at picking up the vibrations of the membrane, severe limitations are encountered when the volume is turned up comparable to an electric guitar, the head vibrates more as the volume increases which causes the instrument to feed back. Pickups have been directly attached to the bridge, for example pickups have been clipped to the bridge itself as described by Cronwell in U.S. Pat. No. 2,725,778 or embedded in a foot of the bridge itself as described by Shubb in U.S. Pat. No. 4,450,744. Unfortunately, these arrangements tend to change the vibration characteristics of the bridge, resulting in tone distortion and still have the volume limitations because the head is not sufficiently dampened from excessive vibration at high volume. These distortions or changes in the sound produced by amplification where taken to an extreme by Rizutti who describes in U.S. Pat. No. 3,192,304 a pickup located on the upper surface of the membrane, fastened to the bridge, which produces "new sounds such as no other electric fretted instrument is able to produce". This still leaves the head free to vibrate and cause feedback.
Thus, there is a continuing need for improvements in stringed instruments to provide improvements in the quality of amplified sound and have the capability of producing greater volume without distorting feedback.